Steam generation.



W. A. BONE, J. W. WLSON & C. D. MCCOURT.

STEAM GENERATION.

APPLICAUON FlLiD JUNE 23, 191|. HENEWED Nov. i8. 1 916.

1,230, 990.. Iarented June 26, 1917.

. ras Partir oraison.

WILLIAM ARTHUR BONE AND JAMES WILLIAM WILSON, OF LEEDS, AND CYRIL DOUG- LAS MCCOURT, OE LONDON, ENGLAND, ASSIGNORS TO RADIANT HEATING LIMITED OF LONDON, ENGLAND, A CORPORATION OF GREAT BRITAIN.

STEAM eENnRATIoN.

Application led June 23, 1911, Serial No. 635,002.

' To all whom t may concern:

f and CYRIL DOUGLAS MCCOURT, resident of 13 Malwood road, Balham IIill,I London, S. W., chemist, subjects of the King vof Great Britain and Ireland, have invented new and useful Improvements in and Relating to Steam Generation, of which the following is a specification. 1

This invention relates to steam generators red with liquid or gaseous fuel, and more particularly to that class ofgenerator in which the fuel is burned in a combustion chamber andthe products of combustion caused to pass through a number of boiler tubes traversing the body of water.

In applying this invention in practice the general plan on which fire tube boilers are at present constructed may be adhered to .with the modifications hereinafter described.

According to this invention combustion takes place primarily in a combustion chamber situated within or in proximity to the shell of the boiler. The boiler tubes through which the products of combustion pass after leaving the combustion chamber are packed or charged with refractory material which.

is desirably in a fragmentary, granular or globular condition. Owing to this packing a much higher heat transmission is obtain- -able per unit areal of tube surface, and we are thereby enabled to reduce greatly the length of tube necessary to effect a-given cooling ofthe furnace gases as compared with the length heretofore generally 1n use.A In order to enable the furnace gases to overcome the resistance to How exerted byv the packing hereinbefore mentioned it is necessary to maintain a sufficient pressure difference between they furnace or. combus. tion chamber and the chimney or oif take. This pressurev difference may conveniently be maintained by means of a fan or other suction appliance connected with the chimney or off take.

In order that the nature'of this invention and the mannerin which it is to be carried into effect may be clearly understood we Specification of Letters Patent.

Patented Juneae, ieir.

Renewed November 18, 1916. Serial No. 132,207.

will describe it with reference to the accompanying drawings in which similar parts are indicated by the like, letters in which Figure 1 is'a sectional elevation of a steam generator constructed according to our invention.

Fig. 2 isa sectional elevation of another form of steam generator constructed according to our invention.

Fig. 3 is a section showing a means of protecting the ,tube plate from eXcessive heating. if

Figs. 4i and 5 represent a device for chargingthe tubes with granular material.

eferring to Figs. 1 and 2 A is a cylindrical boiler shell provided with an internal combustion chamber B and boiler tubes C. D is an offtake connected with a fan or other suction device not shown in the drawings and provided with a door E adapted to give easy access to the tubes for the purpose of charging with granular material as hereinafter described.. Y

The combustion chamber B is provided with a door F preferably lined with fireclay or the like and which may be furnished with suitable openings for the-introduction and lighting of one or more burners of any approved pattern for burning liquid or gaseous fuel. The said combustion chamber B may be lined with rebrick the outline o f which is represented by the dotted line Gr for the purpose-of rendering the combus- -tion more complete. The air required for other suction device hereinbefore mentioned,

and in the ease of liquid fuel being also forced in by the injection of the compressed air or steam supplied to the liquid fuel burners. l

The boiler tubes C are provided with fireclay or the like perforated plugs or ferrulesH adapted to lit the tubes, and are packed with granular refractory material J as for example fire-brick crushed to such a size as will pass a sieve of one mesh to the linear inch, the finer material such as will pass a sieve of two meshes to the linear inch being rejected. The refractory material is retained in position at the other ends of the tubes by metallic grids or spiders K.

Thefire-clay plugs or ferrules while serv-l ing to retain the granular material in the tubes, serve also to protect the tubes at their entrance ends from excessive heating and to direct centrally the hot gases into the granularmaterial, and thus producing at, or about the place where the gases enter the granular material a temperaturehigher'than would beobtained if the said gases were allowed v free entrance over/the entire open end of the tube.

The fire-clay plugs H are by preference so constructed -that while a portion of their length tightly lits'gthe tubes or can be made so to do by winding with asbestos cord or the like, the projecting part H2 of the plug H will taper outwardly so as to retain in position a ganister or like lining L adjacent to the usual tubeplate M which .carries the tubes C and through which the projecting plugs pass.V` This is shown in detail in Fig. 3. There however the tubes are too closely assembled to .admit of the'i above arrangement, the projecting end of the plugs Vmay be enlarged in such a manner as to cover orI vnearly cover the tube plate M when the plugs lare assembled in position, the interstices if any being filled with fire-clay, ganister, or

f other refractory materialofsuch a nature as. 30

to undergo but little shrinkage in burning.

The granular material with which the tubes are'packed serves to greatly'A increase the heat transmission Athrough the walls of the tubes to the surrounding water and in so doing appears to act inthe following manner.- l f ,f

Part of the heat conveyed tothe granular material is radiated thence to the Walls of the containingtube, while-at the same -time the gra nularmaterial serves to miX the gases in transit. continually deflecting gases from the center to the sides andfvice versa.v and repeatedly causing the hot gases to impinge on the walls of the containingl tubef That part of the granular material whiclibecomes incandescent serves to assist the combustion of any part of the fuel which on leaving the combustion chamber is not completely burnt.v We have found as the result of numerous experiments that the intensity of heat transmission through the walls of the tubes depends among other things on the size of the fragments `with which the tubes are packed. The larger the fragments employed the longer will be the tubes necessary to e'ect a given cooling of the furnace gases. We

have found that when the size of the fragments employed is such asV will pass' a sieve of one mesh to the' linear inch but will not pass a sieve of two meshesl tothe linear inch a boiler tube 3 feet long and-of three inches bore is sufficient to cool the furnace gases to a temperature at which they may conveniently be vpassed to a feed-water heaterv .y

With \regard .to the packing of the tubes with granular refractory material, when such tubes are arranged 4vertically the same `may be evenly packed by merely dropping tubesevenly, we use a special tool, (see Figs.

aand' L,coi'fifprr nga disk T having fingers y tifns ar its'periphery the disk being [mounted on 'convenient handle. The granularimaterialifis placed inthe tube and pushed home bythedisk, a-.rotatory or semirotatory motion being given thereto.

Thisl action is continued'until the tubeis filled." c .,1

In previous applications we have described apparatus'for the generation of;.steamwherer.

in are employed packed Atubes provldedlwith lire-clay plugs at their entrance ends, "coin-1 bustion in' one casetaking place in the packed A esv tubes and in another-case the packedftubes serving'ito utilize the heat from hot `waste` Cgase s,and we wish it to be understood that I we do not claim such arrangements jar se.

What we claim as our invention is 1. Steam generating apparatus,Y comprising in combination with a boiler shell, a

combustion chamber` for the prima-ry comv bustion of the fuel, a heating tube traversing the water space of the boiler and leadingy from the combustion chamber to a `suction offtake to receive the combustion gases and,

unburned fuel from the combustion chamber, said tube containing refractory material whereby the transmission of heat toy the water from the hot combustion gases passing through the tube is increased and the compromoted.

. ,2. Steam generating apparatus, compris- `ing in combination with a boiler shell, an

traversing the water space of the boiler andv bustionwithin the tube of unburned fuel is communicating with the combustion cham- I ber to receive the combustion gases and unburned fuel, said tube containing refractory material whereby the transmission of heat to the water from the hot combustion gases passing through the tube is increased and the combustion within the tube of unburned fuel is promoted.

3. Steam generating apparatus, comprising in combination with a boiler'shell, a co'r'ny bustion chamber for the primary combustion of the fuel, a heating tube traversing the water space of the boiler and communieating with the primary combustion chamber to receive therefrom the combustion gases and unburned fuel, and means providing a restricted passage with a wall of rebustion chamber and the tube, and said tube v yfractory material between the primary combeingpacked with pieces of refractory ma.-

-terial whereby the transmission of heatrtofthe water from the hot combustion gases 130 passing through the tube is increased and the combustion within the tube of unburned fuel is promoted.

fl. Steam generating apparatus, comprising in combination with a boiler shell, an internal combustion chamber for the primary combustion of the fuel, a plurality of heat ing tubes traversing the water space of the boiler andv leading from the primary combustion chamber to a suction otake to receive the combustion gases and unburned fuel from the primary combustion-chamber, said tubes .being packed with pieces of refractory material whereby the transmission of heat to the water from the hot combustion gases passing through the tubes is 'Increased and the combustion within the tubes of unburned fuel is promoted.

5. Steam generating apparatus, compris ing in combination with a boiler shell, an internal combustion chamber for the primary combustion of the fuel, a plurality of'heating tubes traversing the water space of the boiler and extending through a tube sheet to communicate with the primary combustion chamber to receive the combustion gases and unburned fuel therefrom, said tubes containing refractory material whereby the transmission of heat to the water from the hot combustion gases passing through the tubes is increased and the combustion within the.

tubes of unburned fuel is promoted, perforated plugs of refractory material arranged in the ends of said tubes which extend through the tube sheet, said plugs having enlarged projecting ends, and a lining of refractory materialfor the tube sheet held by the enlarged ends of said plugs.

6. Liquid heating apparatus comprising in combination with a. liquid receptacle,- an internal combustion chamber for the primary combustion of fuel, a heating tube traversing the liquid space of said receptacle and communicating with the primary combustion chamber to receive the combustion gases and unburned fuel therefrom, said tube containing refractory material whereby the transmission of heat to the liquid fromthe hot gases passing through the tube is increased and the combustion within the tube of unburned fuel is promoted.

7. Liquid heating apparatus, comprising in combination with a liquid receptacle, an internal combustion chamber for the primary combustion of fuel,a heating tube traversing the liquid space of said receptacle and communicating with the combustion chamber to receive the combustion gases and unburned fuel therefrom, and means pro viding a restricted passage with a wall of refractory material between the primary combustion chamber and said tube, and said tube containing refractory material whereby the transmission of heat to the liquid from the hot gases passing through the tube is increased and the combustion within the tube of unburned fuel is promoted.

8. Liquid heating apparatus, comprising in combination-with a liquid receptacle, an internal combustion chamber for the primary combustion of fuel, a heating tube traversing the liquid space of the receptacle and communicating with the primary combustion chamber to receive the combustion gases and unburned fuel therefrom, and a centrally perforated plug of refractory material arranged in the inlet end of said tube and providing a restricted passage between the primary combustion chamber and the tube, and said tube being packed with pieces of refractory material whereby the transmission of heat to the liquid from the hot gases passing through the tube .is increased and the combustion within the tube of unburned fuel is promoted.

9. Liquid heating apparatus, comprising in combination with a liquid receptacle, a

4combustion chamber for the primary combustion of fuel, a plurality of heating tubes traversing the liquid space of the receptacle and communicating with the primary combustion chamber to receive the combustion gases and unburned fuel therefrom, said tubes containing refractory material where? by the transmission of heat to the water from the hot gases passing through the tubes is increased and the combustion within the tubes of unburned fuel is promoted.

In witness whereof, we have hereunto set our hands, in the presence of two witwitnesses.

WILLIAM ARTHUR BONE. JAMEs WILLIAM wILsoN. CYRIL DOUGLAS MCcoUET.

lVitnesses CLEvE WAUGH, CHARLES E. TAYLoR. 

